This proposal seeks support to continue the research and training activities of the Center for Developmental Science for an additional five years. The mission of the Center is to conduct interdisciplinary research on biobehavioral and social development, addressing issues relevant to the health objectives outlined in Healthy People 2000. It is based on the proposition that a simultaneous focus on basic research and applied prevention research is necessary to produce a more robust science and more effective prevention strategies. According to the developmental perspective, the individual develops and functions as a totality. The study of behavior development thus requires attention to the interplay among processes across time frames, levels of analysis, and contexts. The time frames employed should be relative to the lifetime of the phenomena to be understood, hence the periods may be as short as milliseconds or minutes, and long as years or decades. The proposal also calls for more adequate balance in units of analysis. When appropriate, empirical study should extent beyond the individual and dyad to include assessments of the social network, neighborhood, community, and culture. Such extensions require sensitivity to ethnic and community issues, on one hand, and a re- examination of research designs, measurement, constructs, and strategies of analysis, on the other. The collaboration of a community of investigators of investigators on specific research issues seems required in order to effectively address these fundamental issues. The Center for Developmental Science provides a mechanism for such collaboration across universities, disciplines, and academic ranks. Thirty-six researchers from developmental genetics and behavioral neuroscience to life course sociology and developmental psychology participate in the research, training, and scientific collaboration of the Center. Four research programs and five core units are described in this proposal. An Advisory Board of six eminent developmental scientists provides scientific oversight for the Center and its programs, including the review and monitoring of its major empirical research projects and core units, and recommendations for future directions.